The present application relates to a sun-care composition having an SPF value of at least 15 comprising: (a) one or more sun-care actives; (b) a copolymer (or a terpolymer) containing (A) at least one vinyl pyrrolidone monomer and at least one vinyl caprolactam monomer or at least one vinyl acetate monomer or (B) at least one vinyl caprolactam monomer and at least one vinyl acetate monomer; and (c) a cosmetically/dermatologically acceptable vehicle. The sun-care actives include UV-A and/or UV-B sunscreens or mixtures thereof.
More particularly, the present application relates to sunscreen compositions that provide a boost in the SPF value of the composition and provide enhanced sensory properties when applied. Thus, the present application describes compositions that provide efficient photo protection and that can be applied in a smooth, continuous film over the skin which leaves the skin feeling soft and silky.
UV radiation is part of the electromagnetic (light) spectrum that reaches the earth from the sun. It has wavelengths shorter than visible light, making it invisible to the naked eye. These wavelengths are classified as UVA, UVB, or UVC, with UVA the longest of the three at 320-400 nanometers (nm, or billionths of a meter). UVB ranges from 290 to 320 nm. With even shorter rays, most UVC is absorbed by the ozone layer and does not reach the earth.
Sunlight or ultraviolet radiation in the UV-B range is known to be the primary cause of sunburn whereas UV-A radiation, which makes up 90% of solar radiation produces tanning of the skin. However, in that process, UV-A rays cause, in particular, a loss in the elasticity of the skin and the appearance of wrinkles, promoting a premature aging thereof.
Besides the immediate malady of sunburn, excessive sunlight exposure can lead to skin disorders. For instance, prolonged and constant exposure to the sun may lead to actinic keratoses and carcinomas. Another long-term effect is premature aging of the skin. This condition is characterized by skin that is wrinkled, cracked and has lost its elasticity.
Sunscreen compositions are applied to the skin to protect the skin from the sun's ultraviolet rays. Over the past 10 years, awareness of the detrimental effects of unprotected UV exposure has increased and, as a result, consumers are seeking higher levels of protection. Further the standards of the sunscreens have been raised by stringent testing requirements by Regulatory authorities. The most significant changes within these regulations are the new requirements for UVA protection and the added test for photostability of finished sunscreen formulations. The majority of sun-care products currently require SPF levels of at least 30, reaching upwards of 50+. As a result, high levels of UVA protection are required in order to make a UVA claim.
As the sun-are market is becoming more competitive, companies are separating themselves from competitors by launching higher SPF products and thus claiming higher UV protection. To achieve protection across a wide range, sunscreen makers may include several different sunscreen ingredients. One of the most opted way of achieving higher SPF values, is to increase the amount of sunscreens in the product. This approach however will increase the cost of the product and might negatively impact the sensory characteristics of the product. Others have added small amounts of UV absorbers like butyl octyl salicylate as boosters to formulations. Others increased SPF by adding light scattering/refracting polymers to the product such as styrene/acrylates copolymers.
Among the most desirable options is finding a number of absorbers that work in synergy or by using various polymers that provide a continuous film on the skin. A wide variety of cosmetic/dermatological compositions intended for the enhanced performance of sunscreens of human skin is known in the art.
U.S. Pat. No. 6,436,376 discloses a regime/regimen for improved UV-photoprotecting human skin, hair and/or scalp against the deleterious effects of ultraviolet irradiation, comprising topically applying thereon (a) an effective UV-photoprotecting amount of at least one UV-A and/or UV-B sunscreen and (b) an amount of the copolymer tricontanyl PVP (Ganex-WP-660). The compositions are said to be particularly effective for the sunscreen avobenzone.
Similarly, U.S. Pat. No. 6,436,377 claims a regime/regimen for improved UV-photoprotecting human skin, hair and/or scalp against the deleterious effects of ultraviolet irradiation, comprising applying thereon at least one UV-A and/or UV-B sunscreen and the interpolymer PVP/dimethiconylacrylate/polycarbamyl/polyglycol ester in an amount effective to significantly enhance the SPF value.
U.S. Pat. No. 7,368,105 discloses photoprotective compositions comprising at least one dibenzoylmethane UV-screening agent, a stabilizing admixture comprising arylalkyl benzoate compound and at least one bis-resorcinyl triazine compound.
U.S. Pat. No. 4,524,061 discloses polymeric sunscreen agents comprising interpolymers of (a) an olefinic p-aminobenzoate devoid of hydroxy substitution; (b) N-vinylpyrrolidone; (c) a monomer selected from the group consisting of a vinyl lactam having a number average molecular weight of at least 125, an acrylate or methacrylate or any mixture thereof and optionally (d) acrylic or methacrylic acid.
Further, U.S. Pat. No. 5,916,541 discloses a waterproof sunscreen and insect repellent stable emulsion composition comprising an emulsifying agent for forming a stable emulsion; and a film forming agent present in an amount effective to form a thin film when the composition is applied to the skin of a person and provides SPF factors of about 2 to about 50. Poly (vinyl pyrrolidone/1-triacontene) is specifically disclosed.
A consumer consideration while purchasing a sunscreen product is how the product feels and how well it spreads over the skin. Typically, consumers want a sunscreen that feels soft and silky and can be applied in a smooth, continuous film over the skin. Ultimately, product feel could determine whether the consumer decides to purchase the product.
U.S. Pat. No. 7,416,719 describes a sunscreen composition comprising: (a) at least one sunscreen agent; and (b) at least one lauryl glucoside emulsifier, wherein the lauryl glucoside emulsifier imparts an enhanced soft, silky feel to the composition.
With such an advancement and awareness among the consumer, it is always and foremost desired to have sunscreens formulated with the goal of inhibiting skin damage from the sun's rays. The sunscreen composition filters or blocks the harmful UV-A and UV-B rays that can damage and harm the skin. Thus, the present application discloses sun-care compositions with enhanced performance and aesthetics.